griffin



(No Model.) I 2 SheetsSheet .1.

J. H. GRIFFIN.

SEWING MACHINE.

No. 398,323. Patented eb. 19,1889.

(No Model.) 2 Sheets-Sheet 2. J. H. GRIFFIN.

SEWING MACHINE.

No. 398,323.. Patentedf'ela. 19, 1889.

\NITHEEE E.

UNITED STATES PATENT OFFICE.

JOHN II. GRIFFIN, OF BROCKTON, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TOCHURCHILL d5 ALDEN, OF SAME PLACE.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 398,323, dated February19, 1889.

Application filed April 9, 1888. Serial No. 270,022- (No model.)

To all whom it may concern.-

lle it known that I, JOHN H. GRIFFIN, of l'h'ockton, in the county ofPlymouth and State of Massachusetts, have invented certain 5 new anduseful Improvements in Sewing-llachines, of which the following is aspecification.

This invention relates to two-needle sewingmachines, the two threads ofwhich are interlocked by a single lower thread carried by a shuttle.

I'Ieretofore in two-needle machines the needles have usually beenarranged abreast of each other, or so that a line from one to the Iother would be at right angles with the direction of the feed. Needlesthus arranged cannot be used in a machine in which the shuttle moves inthe general direction of, or substantially parallel. with, the feed,because one needle would stand directly between the shuttle and theother needle, so that the shuttle could not obtain access to the loop ofupper thread carried by the farther needle. The use of two needles andtwo upper threads carried thereby, with a single lower thread, hastherefore usually been confined to machines in which the shuttle eithermoves at right angles to the direction of the feed, and therefore .is atthe same distance from both needles, or oscillates in a horizontalplane. The needles arranged abreast of each other, as heretofore, areopen tothe following objectionviz., when the line of stitching iscurved, the distance between the parallel up per thread portions of thestitching is less than when the line of stitching is straight, so thatthere is a lack of uniformity when the line of stitching is partlystraight and partly curved.

My invention has for its object, first, to enable two needles to be usedin amachine having a shuttle moving in the general di-' rection of thefeed-that is to say, with the rotary hook-shuttle which oscillates in aplane parallel with the direction of the feed, or with a reciprocatingshuttle which moves in a straight line parallel with the feed, or withany of the common types of sewing-machines having a similarly-movingshuttle.

The invention has for its object, secondly,

machine with the tl'lroat-plate removed.

to prevent any perceptible variation between curved and straight linesof stitching as to the distance between the upper-thread portionsthereof.

To this end my invention consists in the combinations and arrangementsof parts as set forth in the claims at the end of this specification.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a front elevation of a portion of a sewing-machineof the Singer type provided with my improvements. Fig. 2 represents aview of the opposite side of the portion of the arm of the machine shownin Fig. 1. Fig. represents a top view of a portion of the bed of theFig.

4. represents an end view of a portion of the machine, showing the bedand throat-plate in section. Fig. 5 represents a perspective view of thetwo needles, the shuttle-race and shut tle, and a portion of the bed,the throat-plate being removed. Fig. 6 represents a front view of thehook of the shuttle, the needles, and portions of the needle-bar andtake-up arm. Fig. 7 represents a perspective view of a portion of thetake-up arm, the stud which supports the tension-disks, and thetensionspring on said stud, the tension-disks being removed. Fig. 8represents a perspective view of the under side of a portion of thethroat-plate, the needles, and a portion of the hook of the shuttle.Fig. 9 represents an enlarged top view of a portion of the throatplate,showing the needles therein. Fig. 10 represents a section on line a: m,Fig. 9. Fig. 11 represents a section 011 line y Fig. 9. Fig. 1 2represents a section on line .6 2, Fig. 11.

The same letters of reference indicate the same parts in all thefigures.

I have represented my invention in connec tion with the Singer machinehaving the usual rotary hook-shuttle, a, which oscillates in a planesubstantially parallel with the feed movements of the feed-dog Z).

c 0 represent the needles, which are arranged diagonally, the needle 0being nearer the front of the machine and farther from the shuttle thanthe needle 0, so that neither needle can prevent the loop of the otherneedle T00 scribed arrangement of the needles.

f represents the take-up which supplies thread to the needle 0, and frepresents the take-up which supplies thread to the needle 0. Saidtake-ups are preferably formed on a single arm, h, which is pivoted att' to the neck of the machine and is oscillated vertically, as usual, bya cam, j, on the shaft 71:, which operates the needle and presser-bars.

To supply different quantities of thread to the two needles, so that theloop of the needle 0 will belarger than that of the needle 0, and

will therefore extend across the wider space intervening between theneedle 0 and the shuttle, as shown in Figs. (3 and 11, I give thetake-up fa longer thread- 'mlling' movement than the take-up f. This isaccomplished by locating the takeup f farther from 1 the pivot on whichthe arm h oscillates than the take-up f, as shown in Fig. 2. It will bereadily seen, therefore, that more thread is supplied to the needle 0than to the needle 0 by each downward movement of the take-up arm.

in m m m represent two pairs of tension disks or plates of the usualform pressed together by a spring, a, the pressure of which isadjustable by means of a nut, 0, on the threaded stud 1), which supportsthe tension disks. The threads pass between said disks to the take-upsff.

7' represents a tension-spring, which is secured at its inner end to thestud p and extends outwardly therefrom, its outer portion being bent toform two loops, q q, coinciding with the tension-disks m m. The upperthreads pass through-the loops q c], which exert pressure on the threadswhen the take-up arm is rising. By thus engaging one spring with boththreads I secure a uniform tension on both.

lVhen the work is turned toward the left while being stitched, thestitching is correspondingly curved; but the parallel upperthreadportions, instead of being crowded or brought nearer together by theturning of the work, as would be the case if the needles were abreast ofeach other, remain at substantially the same distance apart as whenstraight stitching is being made, so that there is not a noticeablevariation between the curved and straight lines of stitching as to thedistance apart of the needle-threads on the upper side of the work, thisresult, so far as keeping the curved lines of stitching properlyseparated is concerned, being due to the diagonal arrangement of theneedles.

For sewing seams which are to be curved to the left (which is the usualmanner of sewing seams in sewing scallops on boot and shoe work) theneedles are diagonally arranged, as represented in Fig. 9, or with theneedle which is nearest the operator also nearest to the path ofmovement of the shuttle; but if it be desired to sew seams which are tobe curved to the right this diagonal arrangement of the needles would bereversed, and the needle which is farthest from the operator would beplaced nearest to the path of movement of the shuttle to keep the curvedseams separated.

I prefer to make the eye of the forward needle, 0, somewhat lower thanthat of the rear needle, 0', as shown in Figs. 8 and 10, to additionallyinsure the engagement of the loop of the forward needle, 0, with theshuttle by compensating for the upward movement of the needles thattakes place while the shuttle is entering the loops and for thecurvature of the shuttle when the same is of the rotary hook form hereshown.

The presser-foot t is preferably provided with a spring-arm, a, formedto bear on the outer edge of the work beside the needles to prevent theedge-of the work from sticking to and being partially lifted by theneedles when they are rising.

I claim 1. The combination, in a sewingunaehine, of a shuttle whosemovement is substantially parallel with the feed, two undeflectedneedles arranged diagonally with relation to the movement of the saidshuttle, one of the said needles being thus always nearer to the path ofmovement of the shuttle than the other, and suitable auxiliarystitch-forming devices cooperating with the said shuttle anddiagonally-arranged needles, as set forth.

2. I11 a sewing-machine, the combination, with a shuttle whose movementis substantially parallel with the direction'of the feed and withsuitable auxiliary stitch-forming mechanism cooperating therewith, oftwo undeflected needles diagonally arranged with relation to themovement of the shuttle, and having their eyes arranged at differentheights, as set forth. I

In a sewing-machine, the combination of a shuttle whose movement issubstantially parallel with the direction of the feed, two needlesdiagonally arranged, as described, one of said needles being nearer thepath of the shuttle than the other, and two take-ups engaging thethreads of the respective needles, the eye of thetake-up which deliversthread to the needle farthest from the shuttle being farther from thefulcrum of its take-up lever than the other take-up eye, as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 2d day of April, A. I).1888.

JOHN II. GRIFFIN.

\Vitnesses:

F. M. BIXBY, f rms. 0. llixev.

IIO

